Vikings: from ram-raiders to fishmongers

Experts say commercial fishing may represent the point at which people started to have an impact on marine ecoystems. Photograph: Murdo Macleod

Archaeologists and scientists have revealed that 1,000 years ago cod was traded extraordinary distances across Europe, from the Norwegian Arctic to England and the Baltic.

The research may force yet another revision of the image of the Vikings, from longship ram-raiders, to mainly traders and colonising farmers, to the fishmongers of Europe. Vikings in York were eating cod caught off the Norwegian coast.

Scientists have perfected a technique of analysing cod bones which was originally developed to track modern fish stocks. It analyses collagen, which carries chemical traces of the water the fish originally swam in. Applied to bones from archaeological sites, it is beginning to show a picture of fish transported remarkable distances from AD950 on, when the quantity of bones shows a huge rise in consumption.

The team, led by archaeologists at Cambridge University, say that when fish were chopped up for processing, matching the results from fish bones and heads shows that in some cases they are separated by thousands of miles.

The research, reported in this month's Journal of Archaeological Science, also shows the 1,000-year-old origins of the modern problem of declining fish stocks, as fishing grounds had to supply far more than a local market. The emergence of commercial fishing "may represent the point at which people started to have an impact on marine ecoystems," said James Barrett, of Cambridge University's archaeology department.